At 1/5th of speed of light the probes would cover 1AU in less than an hour, so the visit in the area would be extremely brief. Is there actually a way to get any meaningful data out of it? Or is it just so we can say that we've "been" there?
If every probe manages to capture and transmit a couple dozen pictures while it is within the interesting range, it adds up.
Also these probes could use each other as relays if we send a long string of them towards one destination.
I don't see any discussion of how they propose to tackle that problem.
It makes me think the whole project is not serious, like launching Voyager with no Deep Space Network to listen.
Are they hoping that over the 40 years it takes to get there, a solar-system-sized radio telescope would be built to listen? Even with that it is implausible.
> The sailcraft transmits 100 Watts, deriving its power from a 700-Watt hydrogen beam that is normally incident on the sailcraft when it faces Earth. This hydrogen beam is simply a manifestation of the interstellar medium, incident on the sailcraft at 0.2 c.
From https://arxiv.org/pdf/1805.01306.pdf
> One way to tap the sailcraft’s kinetic energy could be via the interstellar medium: The Local Interstellar Cloud is primarily composed of 0.3 atoms/cm3 of partially ionized hydrogen. From the sailcraft’s perspective traveling at cruise velocity, this manifests as a monochromatic hydrogen beam that is incident from the direction of travel, having a combined kinetic energy of 55W m−2, or 0.7 kW over the sail’s area if it faces the direction of travel.
The report for Starlight suggests a RTG:
https://www.nasa.gov/sites/default/files/atoms/files/roadmap...
Actually it would vaporize any part of the system needed to control or communicate.
Not much room for a light sail large enough to fully offset the power of the launch lasers.